The American Heart Association (AHA) has issued recommendations to help clinicians obtain the most accurate blood pressure (BP) measurements possible, according to a statement published in Hypertension.
Accurate BP measurement is integral to the diagnosis and management of hypertension. In order to ensure the most accurate measurement, the AHA has issued the following recommendations.
Training in BP Measurement
- Assess the physical and cognitive competencies needed to perform auscultatory BP measurement:
- Clinician must be able to see the dial of the manometer at eye level without strain, and they must be able to read the sphygmomanometer no further than 3 feet away.
- Clinician must be able to hear the Korotkoff sounds.
- Clinician must be able to deflate cuff, listen to Korotkoff sounds, and read the sphygmomanometer at the same time.
- Assess the knowledge required:
- Clinicians should know the different types of observer bias.
- Clinicians should know the general techniques and interpretation of the measurements.
- Clinicians should understand BP variability by time of day, exercise, and timing of antihypertensive medication consumption.
- Assess the clinician’s awareness of the need to:
- Use only well-maintained, validated devices
- Choose a quiet location with adequate room temperature
- Correctly position the patient whose BP is being measured
- Make sure that the patient does not talk or move during both the rest and measurement periods
- Make sure the patient does not have a full bladder when BP is measured
- Assess the clinician’s skill in:
- Positioning the patient
- Choosing the appropriate cuff size
- Obtaining a valid measurement
- Accurately recording the measurement
- Reporting abnormal results
Selecting Cuff Sizes for BP Measurement
- Measure patient arm circumference at the midpoint of the acromion and olecranon
- Use a BP cuff bladder length that is 75%-100% of the patient’s measured arm circumference
- Use a BP cuff bladder width that is 37%-50% of the patient’s arm circumference
- Place BP cuff on bare skin
- Do not roll up shirtsleeves as this can create a tourniquet effect
Body Position and BP Measurement
- Compared with the seated position, systolic BP (SBP) may be 3-10 mm Hg higher in the supine position
- Compared with the seated position, diastolic BP (DBP) may be 1-5 mm Hg higher in the supine position
- If the patient is in the supine position with their arm resting on the bed, their arm is below heart level
- The cuffed arm should be supported with a pillow if BP is measured for a patient in the supine position
- The right atrium level is the midpoint of the sternum or the 4th intercostal space in the seated position
- SBP and DBP may increase by 5-15 and 6 mm Hg, respectively, if the patient’s back is not supported
- If a patient’s legs are crossed, this may raise SBP by 5-8 mm Hg and DBP by 3-5 mm Hg
- Readings will be too high if the upper arm is below the level of the right atrium